The present invention relates to image processing. In particular, the present invention relates to an image processing system based upon a vector representation of an image.
An image processing system is a system in which specific features of an image can be identified and acted upon. Typically, an image is entered into the system using an image scanner. The image scanner provides an output which comprises a digital representation of pixel elements. Pixel elements are representations of intensity of discrete portions of the scanned image. A pixel may indicate whether a discrete portion of the scanned image has an intensity which is greater than or less than a threshold level. In this case, the pixel representation of the image will be a plurality of dots in which the dots are either black or white. Pixels may also represent gray scale or color of the image.
Image processing has become increasingly important in recent years. Much modern technology uses images as a source of information for interpretation and analysis Images may be from satellites, x-rays, microscopes, flat bed scanners and facsimile machines. The proliferation of these image sources has created a need for image processing that can rapidly, accurately and cost effectively extract information contained in images.
Computers can process scanned images and perform various types of interpretation and analysis. These include image enhancement, distortion correction and pattern recognition. Image processing can be used in production testing and quality control, robotics and other activities where it is desirable to rapidly and cost effectively extract useful information from scanned images. For example, image processing can be used for optical mark recognition such as described in U.S. Pat. No. 4,571,699. In such a system, a marked answer sheet such as those used in standardized tests is scanned into an image processing system which processes the results and identifies the number of correct answers.
Typically, image processing systems operate on individual pixel elements or strings of adjacent pixel elements to analyze the image.
There is a continuing need to improve the speed, accuracy and capabilities of image processing systems.